Organo-lithium derivatives of alpha-silylmethyl sulfides

ABSTRACT

ORGANOSILYL COMPOUNDS OF THE FORMULA   R&#34;-S-C(-LI)(-R&#39;&#39;)-SI(-R)3   WHERE R IS HYDROCARBON, H, OR NX2, R&#39;&#39; IS R3SI-OR HYDROCARBON, R&#34; IS ALKYL OR PHENYL AND X IS ALKYL ARE PREPARED BY REACTING   R&#34;-S-CH(-R&#39;&#39;)-SI(-R)3   WITH ALKYL LITHIUM COMPOUNDS. THELITHIUM COMPOUNDS ARE USEFUL AS POLYMERICATION CATALYSTS FOR STYRENE.

3,555,066 ORGANO-LITHIUM DERIVATIVES F ALPHA-SILYLMETHYL SULFIDES GaryE. Le Grow, Midland, Mich., assignor to Dow Corn'jng Corporation,Midland, Mich., a corporation of Michigan No Drawing. Filed Dec. 13,1968, Ser. No. 783,748 Int. Cl. C07f 7/08, 7/10 US. Cl. 260-4481 ClaimsH RaSi-C-S R" L,

with alkyl lithium compounds. The lithium compounds are useful aspolymerization catalysts for styrene.

This invention relates to compounds of the formula 1|.i RAE- s R 2-:

where x is 1 or 2, R is R" Si or a hydrocarbon radical free of aliphaticunsaturation, at least one R being R" Si in which R is hydrogen, ahydrocarbon radical free of aliphatic unsaturation or X2N'- in which Xis an alkyl radical and R is an alkyl or phenyl radical.

As can be seen the compounds of this invention include structures of theformulae The compounds of this invention are best prepared by reacting RCH SR' where x is 1 or 2 with an alkyl lithium compound in the presenceof tetra-hydrofuran. The usual precautions to exclude moisture andoxygen should be used as with any organo-metallic reaction. The best wayof carrying out the reaction is to add the alkyllithium compound to asolution of the silyl sulfide in tetrahydrofuran at a temperatureranging from 0 to -40 C. Carrying out this reaction at low temperatureavoids undesirable side reactions. The rate of addition should besuchjthat the approximate temperature range is as above specifiedthroughout the reaction. Once the compound application filedconcurrently herewith. The lithium compounds of this invention are alsouseful as catalysts in the United States Patent 0 Patented Jan. 12, 1971polymerization of olefins such as styrene in which stereo regularpolymers are produced.

The starting materials of the formula R" SiCH SR can be prepared byreacting known compounds of the formula R" SiCH Cl with NaSR' in thenormal manner for reacting sodium salts of mercaptans with haloalkylcompounds. Those starting materials of the formula with R1 as shown inExample 4 infra.

Those starting compounds of the formula are best prepared in accordancewith the method set forth in applicants copending application Ser. No.783,749 filed Dec. 13, 1968 which is hereby incorporated in its entiretyby reference. This involves the reaction of compounds of the formula:[Li R". s1 |3-s R H with R" SiCl in amount of 1 mole of the latter permole of the former.

For the purpose of this invention R can be any alkyl radical such asmethyl, ethyl, isopropyl, butyl, octadecyl or myricyl; any aryl radicalsuch as phenyl, naphthyl,

. anthracyl or xenyl; any alkaryl radical such as tolyl, xylyl orethylphenyl; or any aralkyl radical such as benzyl, betaphenylethyl orbeta-phenylpropyl. R can also be any R Si radical in which R" ishydrogen or any alkyl, aryl, aralkyl or aralkyl radical shown above or Rand in addition R" can be a X N radical in which X is an alkyl radicalsuch as methyl, ethyl, isopropyl or octadecyl.

For the purpose of this invention R can be any alkyl radical such asmethyl, ethyl, isopropyl, hexyl, octadecyl or myricyl; or the phenylradical.

In addition to the utilities shown above the compounds of this inventionare useful as intermediates in the synthesis of other organosiliconcompounds such as those shown in the aforesaid copending application.They can also be used for synthesizing other organic compounds.

The following examples are illustrative only and should not be construedas limiting the invention which is proper- 1y delineated in the appendedclaims.

EXAMPLE 1 0.125 In. of (CH SiCH SCH was dissolved in 200 ml. oftetrahydrofuran and cooled to -25 C. 0.125 m. of n-butyllithium in ml.of hexane was then added slowly with stirring and the temperature washeld at 25 C. for an additional hour. The solution was allowed to warmto room-temperature.

A N.M.R. spectrum was run on a 10% solution of the product and peaksappeared at 10.02 and 10.07 tau. These peaks are not present in thespectrum of (CH SiCH SCH or in the spectrum of butyllithium. The peaksrepresent the presence of carbanion Li (CH;) SiC:SM

As further proof of structure of the lithium derivative the product wasreacted with 1.59 moles of methyl iodide at room-temperature. Water wasthen added and the product was extracted with ether. The extract wasdried and the product was distilled to give an 85% yield of thederivative (13H: (CHahSiCHSCHs The structure of this derivatve wasproven by N.M.R. and elemental analysis. It boils at 81.5 C. at 70 mm.has a refractive index at 25 C. of 1.4537, a density at 25 C. of 0.846and a specific refraction found 0.3199 and calculated 0.3198.

with butyllthium as in Example 1, the compound {(CH Si} CLiSCH isobtained.

EXAMPLE 3 When t (CH )3SiCHSCH is used as a starting material in theprocess of Example 1, the compound Li (CHmSiCSCHa is obtained.

EXAMPLE 4 A solution of 0.1 rn. of (CH SiCH SC H in 50 ml. oftetrahydrofuran was cooled to -30 C. and .05 m. of n-butyllithium in 32ml. of hexane was added over a minute period. The solution became brightyellow. It was stirred an additional 2 hours at 30 C. The bright yellowcolor was due to the formation of 1|.i (CH SiCHSC H The structure wasfurther proved by the addition of methyl iodide to give a clear solutionindicating the formation of (IJHa (CH hsiCHsCsHa EXAMPLE 5 The compound(CI-IahNSiCHSCH;

was made by reacting C151 0 HS CH with two equivalents of (CH NH inhexane at roomtemperature. .039 mole of (CH3)zNSiCHS CH3 was dissolvedin 60 ml. of tetrahydrofuran and .039 mole of butyl lithium in 25 m1. ofhexane was added at 0 C. The solution turned bright yellow and wasstirred for one hour. The compound (C H 2 Li (CH 2NSi- S CH2 wasobtained.

The compound C ISi C H S C H; m

was prepared by reacting vinyldimethylchloromethylsilane with methylmercaptan in the presence of a small amount of azo-bis-butyronitrile atroom-temperature under ultraviolet light.

EXAMPLE 6 When ClSiCHSCHg 11H.

is reduced with lithium aluminum hydride the compound HSlCHSCHg isobtained.

When this compound is reacted with n-butyl lithium in accordance withthe procedure of Example 5, the compound (CH Li HSiCSCH is obtained.

6 That which is claimed is: EXAMP 7 1. A composition of the formula Whenthe following silanes are substituted in the pro- Li cedure of Example1, the following products are obtained:

I RxCH2-xs R in which x is an integer from 1 to 2, R is selected fromthe group consisting of hydrocarbon radicals free of aliphaticunsaturation and radicals of 10 the formula R" Si at least one R beingR" Si-,in which R" is selected from the group consisting of hydrogenatoms, hydrocarbon radicals free of aliphatic unsatura- Silane Producttion and X N radicals in which X is an alkyl radical and CH CH L m m 1 Ris an alkyl radical or a phenyl radical. C HwS iCH S CisHa1 1831315 1 CS Cia s1 2. A compound of the formula H31 15 31 L CH3 CH3 Li I 1{(CH)N)2SiCH2SCH3 l(CH3)zN)ziJJHSCH3 2 (CEmaSiGHSCHa a Li 0 3. Acompound of the formula (oarmasiomscm (CGHmSiC EHSCHQ CH) (CH) Li(CHa)3S1OHSCaH a 2 a 2 4. A compound of the formula CHaCHCHzSiCHzSCHaCH3CHCH2SiCHSCHs I (CH3)2 L1 6,11, (3,11 (CH3)2NSiCSCHa a): Hsh 1 s-sicms c11 @g' cns 5. A compound of the formula Iii (011m Illi Li H S iCS CH3 I (CHeJaSiCHSCHs (OHahSiC-SCH; CH3

(38115 References Cited 3119 3 UNITED STATES PATENTS omouansioms 0H;CHaCaHlSiOHS 011 ,492 11/ 1960 Morton et a1. 260-448.2XR I 3,078,292 2/1963 Prober 260448.2(N) Li TOBIAS E. LEVOW, Primary Examiner (CHmS iCH SCH5 (011535! S CH5 P. F. SHAVER, Assistant Examiner 1-1 H I 2 2 US. 01.X.R. CnHs 00115

